sub suggestion?

[mikeinaus]

im planning on making a sub box to fit into the spare tire well and im looking for suggestions on a 10" or 12" sub to look for.

my amp is a mono block phoenix gold octane r 8.0:1 (description herehttp://reviews.cnet.com/car-amplifiers/ ... ml#manDesc
power output is 800w peak
400w at 4ohm
600w at 2ohm

im hoping to find a sub for a decent price $150+/- that would be as close to a perfect match with my amp as possible. the enclosure will be sealed and made out of mdf or plywood depending on weight. im planning on making it a D shape and take up about 80% of the spare tire well, so should have a decent cubic feet to it.
any suggestions would be greatly appreciate as i know almost nothing about car audio...

btw clarity and quality are more what im looking for rather then mind blowing bass

[carizle]

The the box is more important than the sub. Whichever speaker you get try to match it with the box. But I like Kickers, JL...I had some Kenwoods that I got a great deal on that sounded great (KFC series). Check out Crutchfield.com. Also if your going to run just one speaker make sure its a dual voice coil so you can wire it to get the most from your amp-to run the 2 ohm @ 800 watts. Alot of JLs are DVC as are Rockfords. And I believe the Alpine Type R is as well.

[PATDIESEL]

I would suggest another route for building the box. The subs Carizle suggested are all ok, but for pure clarity I like Boston Acoustics in a sealed box.
As for building the box, have you thought about a fiberglass mold of the tire well. The reason I say this is that I am not sure you are going to get much volume from a wooden box that will fit into that mini-tire's hole. To build the box would really be pretty easy, you use duct tape and tape all around the inside of the tire well and well over the edge onto the flater surface of the hatch. Then mix some resin, lay a layer of glass fabric into the well and start pouring the resin over the faric to wet it out. Repeat this 5 or 6 times to build a nice thick fiberglass mold of the well and it will be larger (more air space) and stronger than a wooden box too. Once it is dry you will pry it out of the hole and attach a wodden top side with the speaker hole cut in it. Then seal the two pieces together with some fiberglass resin and a few screws. Carpet the wooden top, insert the speaker and viola, Awesome easy to build speaker box.
Protect the rear bumper and other pieces from resin spills with a plastic tarp or paint tarp from home depot. Cheap and works well. use rubber gloves and feel free to contact me via PM or on the MOCA forum and I will be happy to help you along.

[Daninski]

Pat I like your idea and I was wondering, as a mold release agent would using something like dry cleaner plastic work? I would think that would make it real easy to pry out the form once it's cured. Personally, I've used spray wax like Pledge or a store bought mold release agent but from what I'm reading your saying this isn't necessary.
To protect the speaker I thought covering the opening with Pet Grade black door screen for dust and particles and expanded metal on top for anything heavy that ends up on top of the speaker.

Sorry for hijacking your thread Mike but I thought these questions/suggestions would be of help to both of us.

[carizle]

Products like Plastiease and honey waxes made specifically for fg are kind of expensive some use cooking spray for a mold release.

Oh and if you go 'glass make sure you have a warm workspace or it won't cure and harden properly. But the odors can linger for quite awhile if indoors my extra bedroom smelled like fg resin for almost a year and I even had the windows open with a fan blowing out whenever I was working
Youtube has a lot of 'glass how to's to give you tips, but its not difficult, just messy. Only thing to watch for is when its hard you should be able to put all your weight on it without any flexing. add more layers until rigid or it will sound like crap whether you have a cheap Walmart sub or a nice Boston or Infinity. Also people often add filler to the box it increases the sound quality and makes the sub act as though the box has more airspace.

[mikeinaus]

how long does it take for fb to harden? i live in a pretty sketchy area and i dont think itd be very wise to keep my trunk open for an extended period of time. i also wouldnt want my car to stink like fb for god knows how long.

i also thought its better for the boxes to be heavier to transfer bass better or is that complete bs?

[Ryan]

FG should cure to the touch in ~6 hours, depending on the resin you use. It cures faster in warmer weather.

Yeah, thats BS. The dimensions and volume will change the resonant frequency(ies) of the box, as well as the strength of the bass(but bigger is not better, there is an optimum). Box design depends entirely on the sub you're running. The manufacturer will have recommended volumes, I'd go with that. Its usually on the manufacturer's website. Each sub has strengths in certain ranges, and the box tries to tune those down and tune up the weaker range, etc. The manufacturers will do a massive amount of testing, and solve some differential equations, likely using numerical methods, and voila, ideal dimensions.

But this is a FG formed box, you get what you get.

[Daninski]

You can add extra hardener to the polyester resin and do a 'hot cure'. I've had my resin set up in 20 mins. no problem. Ryan are you sure you weren't talking about epoxy resin set times?
One way or the other the part will need a place to 'off gas' and that preferable won't be in your car.
When and if you grind down the edges be sure to wear a mask.

[Ryan]

Dan you're right, I definitely shouldn't have said to the touch. My bad. But I wouldn't try to remove to mold in 20 mins...

[john1983]

Why not make a mold of your spare tire well with some thing else that you could take out and make the fg mold with that and then you could let it set in your garage or where ever, so you wouldnt have to worry about the smell in your car? Just a suggestion, I have never worked with fg myself so it could be pointless. I just figure if you can make your mold and let it set up outside of your car then you would be able to avoid the smell and still use your car while the fg is hardening.

[mikeinaus]

at the moment im considering getting a cordless grinder and cutting the spare tire well out of a car at the wreckers. thatd give me a nice mold to make a fiberglass box without it smelling up my car or have any problems with theft...

[Ryan]

Maybe I was being pessimistic. I bet you could let it set up for 2-3h on a sunny day with the hatch open and be fine. Just sit on your... driveway with a lawn chair and a beer, maybe do an oil change... clean up some stuff...

[neuspeedescort]

when i do glass projects this big i generally lay 4-5 layers of glass before pulling it out. once out i iwll add more so im not busting my back the entire time. cure time is so product and weather dependent. i play it safe and let it cure over night. so start the build on a friday night and let it sit over night before releasing it from the "mold". when you crawl otu to it on saturday morning it will be hard. if it isn't you did somethign wrong.


NEUMAN

[mikeinaus]

i started making my box last weekend and its going pretty well. i ended up going the fb route and other then being extremely messy its turning out well. id say im about 50% complete but im not in that much of a rush to finish it.

tonight im going to pick up a 500W rms dvc 2 ohm alpine type R 12" sub. im planning on powering it with my phoenix gold octane R 8.0:1 monoblock. the problem is my amp outputs 600w rms at 2 ohm and 300w rms at 4 ohm. assuming the amp is tuned properly should i be worried about overpowering the sub by 100w rms?

[john1983]

it could hurt the sub but i have ran subs on amps that put out more then the sub was rated for just did not turn the gain up to high. So as long as the amp is tuned rite you should be fine imo.